MEMS is a micro-integrated system that fabricated by fabricating microstructures, microsensors, microactuators, control processing circuits, and even interfaces and power supplies on one or more chips using integrated circuit (IC) fabrication technology and microfabrication technology. Compared with conventional infrared detectors, infrared detectors fabricated using MEMS technology have obvious advantages in terms of volume, power consumption, weight, price, and so on. Nowadays, infrared detectors fabricated using MEMS technology are widely used in military and civilian fields. According to different working principles, infrared detectors are mainly classified into thermopile detectors, pyroelectric detectors, thermistor detectors, and so on. The thermopile infrared detector converts a temperature change caused by infrared radiation into a voltage signal according to the Seebeck effect, and then outputs the voltage signal. The pyroelectric infrared detector measures the temperature change caused by infrared radiation by accumulation of electric charges in a heated object. The thermistor infrared detector measures the temperature change caused by infrared radiation by reading a change in resistance of a resistor. At present, MEMS infrared detectors are generally single-layer suspended microstructure, of which a process is very simple, but when a size of an infrared detector chip is reduced, a suspended absorption region (film absorption layer) used to absorb infrared radiation will be correspondingly reduced, which will greatly reduce an infrared response rate of an infrared detector.